WINTER PLANTS GIVE US SOMETHING TO THINK ABOUT

by Whit Gibbons

December 17, 2017

Plants with bright flowers and trees with tender, green leaves abound in spring and summer. In autumn, different flowers and colorful leaves make an appearance. But what do plants offer us in winter? I took a walk in my neighborhood and nearby woods to appreciate the variety of plants to be seen and to look for native plants that remain green through the winter.

Many yards on my street have evergreens, including azaleas, camellias and gardenias. Where did they come from, and are they related to any native plants? The first camellias to arrive in the United States were brought here in the 1700s from England and were descendants of ones originally imported from Asia. Common gardenias have a similar history. Both are products of centuries of enterprising horticulturists. No native plant belongs to either genus, and although biologically distinct, gardenias and camellias have something in common. Both belong to plant families responsible for two of the most widely drunk beverages in the world. Gardenias are in the coffee family (Rubiaceae) and camellias are in the tea family (Theaceae).

Azaleas (genus Rhododendron) are in the heath family, Ericaceae. Most evergreen azaleas seen in yards, along golf courses and in city parks are horticultural varieties of Chinese origin. Some rhododendrons native to the Appalachians also remain evergreen. During my walk in the woods that day, I looked for and found several wild natives – swamp azaleas. These large shrubs are deciduous, losing their leaves in the fall but sport beautiful pink and white flowers in early spring before they leaf out. Whether native or introduced from another continent, whether evergreen or deciduous, each member of these three plant families has a beauty of its own.

On this excursion, the woods were more interesting than the neighborhood to me. Natural forests comprise a higher diversity of trees, shrubs and other plants with a variety of strategies to survive the transition from summer warmth to winter cold. Most of the plants in the woods are deciduous, dropping all their leaves in autumn. Brown and leafless plants can have their own appeal, but I wanted to find native plants that stay green in wintertime. A walk in the forest with such a goal can be an interesting exercise in most eastern states outside of Florida. In many parts of Florida, the majority of plants would be green, and a non-botanist would be hard put to identify trees or shrubs that were not from another continent.

In my own woods, I narrowed the field of evergreen trees pretty quickly with the conifers – longleaf, shortleaf and loblolly pines and a few red cedar trees managing to survive in a mostly hardwood forest. Most conifers, including firs and spruce, as well as cedars and pines, retain their green needles. Bald cypresses, however, which are also conifers, do not. I looked at a small, lonely cypress standing bare and needleless alongside the stream and wondered why it was different from its evergreen cousins. Botanists may debate why some trees have evolved to lose their leaves and others to stay green. Why a short, seemingly lifeless bald cypress is never anyone’s conifer of choice for a Christmas tree seems obvious.

Most temperate zone hardwoods like maples, dogwoods and hickories lose their leaves. But American holly, Carolina cherry and sweet bay magnolia stay green all year. Evergreen trees do shed their needles or leaves over time, replacing them with new ones. Brown pine needles and holly and magnolia leaves at the base of the trees are evidence of that.

Field guides to the plants in your area offer information about native and introduced species. And having one with you can turn a walk around your neighborhood and through the woods into a learning adventure. Or you can just take a wintertime walk and admire nature’s myriad wonders. You do not need to be a botanist to notice different approaches plants have for dealing with cold weather.

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